This study will provide a new investigator (an epidemiologist and electrical engineer) with the opportunity to work with experienced researchers in the fields of epidemiology, ergonomics, occupational health medicine, bioengineering, and electrical engineering in developing an objective technique for detection of upper extremity musculoskeletal disorders (UEMSDs). Training components will include image processing and biophysical modeling. The long-term objective of this study is to evaluate the efficacy of infrared thermography in the dorsal hand for detection of sub-clinical distal UEMSDs. The goal of the proposed study is to expand a prior pilot study, in which office workers were subjected to a typing challenge in conjunction with thermography. New elements will include improved ambient temperature control, blood flow measurements, and detailed clinical evaluation in order to improve case characterization. The specific aims seek to evaluate the suitability of thermography for evaluation of UEMSDs and for improved understanding of UEMSD pathophysiology. These include assessing the reproducibility of dorsum mean temperature thermography (DMMT), determining the relationship between skin temperature and subcutaneous blood volume as measured by near-infrared spectroscopy, and using DMMT to investigate differences between symptomatic and asymptomatic office workers.